Solar Wax Melter

1. Measure your pan.  This will determine the dimensions of the entire box.  We use a cheap, aluminum roasting pan, 17” by 12” by 3” deep. Try to keep this container 3” deep or less, and metal is preferable.
2. You want your inner box to be 1” larger on all sides than your pan.  In this case, the inner box will by 19” by 14”.  Because we will be using 1X8 lumber as the outer box, and we will have 1” of insulation below the inner box, the inner box height will be 7”.
3. Your outer box will be 3” larger on both sides than the pan (1” for inner box + 2” insulation).  Our outer box size is 23” by 18” by 8”, inside dimensions.  You can adjust your dimensions according to materials on hand.

1. Cut your sheet metal according to the picture.  You should end up with 4 pieces of metal.  One piece will be 14” by 39”, 2 pieces at 11” by 25” and one piece at 22” by 25”.
2. Using the 14” by 39” piece, bend according to the picture.  Start at 3”, bend away from you, at 10” bend towards you, at 29” bend towards you, and at 36” bend away from you.  You will be creating a U shape with 3” wings. You should now have 2 sides and the floor of the inner box.
3. Starting with one of the 11” by 25” pieces, mark along both 25” edges at 3” and 22”. Draw lines between these marks. Along the 11” edges, make the following marks: 1”, 7” and 8”.  Draw lines between these marks.
4. Using tin snips, cut from the 25” edge on each line until it cross the line at 8”.  Now, along the 7” line from the 11” edge, cut until you reach the slice you just cut. Do not discard this scrap piece, we will use it later. You should now have a T shape piece with small tabs.  Follow the same procedure for cutting the other 11” by 25” piece of sheet metal.
5. Bend each 11” by 25” piece of sheet metal according to the diagram.  Start by bending along the 1” line towards you.  Flip the piece over, and bend from the end of each slice towards you.  You now have the remaining sides.
6. Using the scrap pieces from step 2d, bend them in half to form a corner piece.
7. Take the large U-shaped metal piece from step 2b and one side piece from step 2e.  Place the side piece with it’s 1” tab under the bottom of the large U.  Using self tapping sheet metal screws, attach the two metal pieces together, screwing through the bottom of the large piece into the tab of the side piece.  Use 4 screws.  Follow this procedure for the remaining side from step 2e.  You should now have a basic box.
8. Screw the corner pieces from step 2f on each corner of the box.  The corner pieces should be on the outside of the box, and you should screw from the inside out.  Be careful to avoid getting nicked by protruding screws. Use 4 screws for each corner piece.
9. The inner box should be ready for paint.  Apply 2 coats of black paint to the inside of the box only. Do not paint the upper edge of the box.

1. Start by marking the 1X8 by 8ft board at the following intervals: 23”, 46”, 66” and 86”.  Using a circular saw, cut the board at these marks.
2. Using the 2 20” long pieces, make 2 pilot holes on each end.  The pilot holes should be 1/2” from the edge. Use the 1/4” drill bit to make these holes.
3. Find a flat surface, and stand all 4 boards up to form a box.  The 23” long boards should go inside the 20” boards. Use 1 1/2” wood screws and assemble the boards together, using the pilot holes for the screws.
4. Measure the halfway point on both 23” board, near the bottom edge of the box.  Drill a pilot hole on each halfway point, 1/2” from the bottom edge. Cut a 18” piece of 1X1, and insert it between the 23” board at the halfway point.  Make sure this board is flush with the bottom of the box and screw it in place using 1 1/2” wood screws.
5. From the remaining scrap sheet metal from Step 2, cut a piece 25” by 20”. Using 3/4” wood screws, attach this to the bottom of the outer box. Use the middle support board as additional reinforcement for the bottom.  Place a screw every 4” or so around the perimeter of the box.

For insulation, we use perlite, but any loose fill material should work well.  Sawdust, rice hulls, vermiculite, shredded paper, and wood ash are good candidates.

1. Place a layer of insulation in the bottom of the box.  Fill to the top of the 1X1 bottom support board.
2. Place the inner box into the outer box.  Center the box so that you have a 2” gap on all sides.  Fill this gap slowly with insulation.  You may have to bend the metal tabs up a bit to allow for access to the space.  Fill a little at a time, moving around the box, so that all edges fill at the same rate.  Periodically, stop filling and gently pack the insulation into the space.  Continue filling all the way to the top.
3. Using 3/4” wood screws, attach the metal tabs of the inner box down to the top of the outer box.  Start at one corner and work your way around.  The small tabs from the short sides of the inner box should lay under the tabs from the larger sides.
4. Go around the edges with a hammer and bend the metal down to avoid any sharp, dangerous protrusions.
5. Seal all cracks and seams with silicon and let dry.

1. Cut two pieces of 1X2 25” long, and two pieces 22 inches long.  Drill 2 pilot holes on each end of the 22” pieces, 1/2” from the edge.  Layout out the rectangle on a flat surface.  The 25” pieces should go inside the 22” sides.  Screw them together.
2. Cut a section of greenhouse plastic, 27” X 24”.  Lay this over your rectangle, and staple one edge to the side of the rectangle.  Staple around the perimeter of the rectangle, pulling the plastic tight.

1. Cut two pieces of 1X1, 17 inches long.  Cut two more pieces 10” long.  Drill a pilot hole on each end of the 17” pieces, 1/2” from the edge.  Layout out the rectangle on a flat surface.  The 10” pieces should go inside the 17” sides.  Screw them all together.
2. Staple an edge of the shade cloth to the side of your rectangle.  Pull the shade cloth tight, and staple the opposite side.  Go along the perimeter of the rectangle, and staple the shade cloth all the way around, pulling it tight as you go.

The Solar Wax Melter is easy to use.  In the morning of a bright, sunny day, place a few chunks of comb on the screen.  Adjust the orientation of the box throughout the day so that it tracks the sun.  The wax should melt fastest between 10 am and 2 pm. We are able to melt a full comb in 10 minutes during the hottest hours of the day.

It is a good idea to place a few small stones on the lid to help hold the plastic against the rim of the inner box, making a good seal. The box should obtain temperatures of 200 degrees F or more.

When the wax has melted, remove the pan and pop out your chunk of wax.  You can continue to add comb to build up a large chunk of wax for storage or projects.

The wax melter can also be used as a solar oven for cooking small meals or pasteurizing water when you’re not melting wax.